Effects of ascorbic acid and glutathione treatments on litchi fruits during post harvest storage

To investigate the effects of ascorbic acid (AsA) and glutathione (GSH) on the preservation of litchi fruits, three groups of harvested fruits were used in the experiment. Group One was immerged in a solution of 50 mmol/L ascorbic acid combined with 500 mg/L carbendazim+3 mL/L sportak+15 mmol/L citric acid for 5 min; Group Two in 50 mmol/L glutathione combined with 500 mg/L carbendazim+3 mL/L sportak+15 mmol/L citric acid for 5 min; and Group Three, as control, in 500 mg/L carbendazim+3 mL/L sportak+15 mmol/L citric acid for 5 min. All the samples were dried at 18°C in the air-conditioned room. Then, each group was divided into two sub-groups: one was stored at the electric thermostat-box at 6°C with 80% relative humidity, and the other was stored at room temperature. Compared with the control, both AsA and GSH treatments reduced the activities of PPO and the relative electric leakage in pericarp, significantly enhanced the activities of SOD, CAT and reduced the content of H2O2 and MDA in pulp. AsA and GSH treatments also increased the content of vitamin C and GSH in pulp. Both AsA and GSH treatments effectively preserved fruits in low temperature and reduced the decay rate of fruits, but AsA treatment was more effective than GSH treatment. AsA treatment was also effective in room temperature while GSH treatment was not.